ABIDJAN (Reuters) - Ivory Coast has closed its land borders with Ebola-affected West African neighbours Guinea and Liberia in an attempt to prevent the world's deadliest outbreak of the virus from spreading onto its territory, the government announced.

A number of African nations have defied advice from the World Health Organization (WHO) and put in place restrictions on travel to and from the countries where Ebola has appeared, which also include Sierra Leone and Nigeria.

The Philippines on Saturday ordered 115 troops to return home from peacekeeping operations in Liberia due to the outbreak there.

Ivory Coast, French-speaking West Africa's largest economy, had previously imposed a ban on flights to and from Sierra Leone, Liberia and Guinea.

"Faced with new outbreak sites and the reactivation of old sites...the Ivorian government decides to close its land borders with sister republics Guinea and Liberia," said a statement read on state-owned television late on Friday.

Liberia's Nimba County, which shares a border with Ivory Coast, has seen the number of Ebola cases balloon in recent weeks. According to Moses Massaquoi, the head of Ebola case management at Liberia's health ministry, 65 cases including 25 confirmed patients have now been reported there.

"The number of cases in Nimba has spiked recently and it is now an area of concern," Massaquoi told Reuters.

Ebola has killed 1,427 people out of 2,615 known cases identified since the West Africa outbreak was first identified in Guinea in March, according to WHO figures released on Friday.

However, families hiding infected loved ones and the existence of "shadow zones" where medics cannot go mean that the true scale of the epidemic is unknown, the U.N. health agency said.

The WHO has repeatedly said it does not recommend travel or trade restrictions for countries affected by Ebola, saying such measures could heighten food and supply shortages.